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CIEN SCHEDULE 13G/A: SEC filing

A Schedule 13G/A amendment was

Filed with the SEC on · accession 0000019617-26-000338

CIEN filed a SCHEDULE 13G/A (schedule 13g/a) with the SEC on Sep 3, 2026. A Schedule 13G/A amendment was filed regarding CIENA CORP, indicating a change in a passive institutional holder's ownership position. The stock moved -10.4% by the first close after the filing.

Summary of the filing

A Schedule 13G/A amendment was filed regarding CIENA CORP, indicating a change in a passive institutional holder's ownership position. The filing text provided contains only the EDGAR directory listing and no substantive ownership details.

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Key details

IssuerCIENA CORP

How CIEN stock reacted

Close before

$354.16

Sep 2, 2026

First close after

-10.36%

$317.46

5 trading days

-5.53%

$334.56

Since filing

-34.83%

$230.81

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Frequently asked questions

What did CIEN file with the SEC on Sep 3, 2026?

CIEN filed a SCHEDULE 13G/A (SEC filing). A Schedule 13G/A amendment was filed regarding CIENA CORP, indicating a change in a passive institutional holder's ownership position. The filing text provided contains only the EDGAR directory listing and no substantive ownership details.

How do I read a SCHEDULE 13G/A?

A report the company filed with the SEC (the US market regulator). Start with the summary, then the key amounts and names. Compare it with the company’s earlier filings.

Why are SEC filings important?

Public companies must tell the SEC about anything that can change their value — results, leadership changes, big deals, new shares, bankruptcy. Filings are the official source, often before the news. A SCHEDULE 13G/A (schedule 13g/a): A report the company filed with the SEC (the US market regulator).

How did CIEN stock react to this filing?

CIEN closed at $354.16 before the filing and $317.46 on Sep 3, 2026 (-10.36%). Five trading days later: $334.56 (-5.53%).

Other CIEN SEC filings

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